Study the effects of deep eutectic solvent choline chloride: glycerol on kinetic properties of wild-type and mutant luciferas

Firefly luciferase is a light generating enzyme, which is used in different fields of biotechnology and molecular biology. Luciferase has found widespread applications in many areas of genetic analysis such as detecting gene expression, reporter gene assay and proteomics studies such as protein-protein interactions. Despite many advantages, there are some limitations in luciferase-based systems, the most important of which is its low stability. One of the newly developed methods to solve this problem is to take advantage of Deep Eutectic Solvents (DES). One group of DESs is those that composed of organic salts with hydrogen donor, due to which, intermolecular hydrogen bonds cause lower melting point in comparison with each of the component. In this study, we investigated the effects of DES on kinetic properties of wild type and I232R - E354R/Arg356 mutant Lampyris turkestanicus luciferases. For this, both enzymes, wild type and mutant, expressed in BL21, the protein of interest purified through affinity chromatography and used for kinetic studies. Here, we used choline chloride: glycerol as DES. According to the results, the wild type luciferase is much more thermostable in DES than I232R - E354R/Arg356 mutant. Furthermore, the remaining activity of both wild type and mutant luciferases are greater in the presence of DES than those in the absence of DES.